By a virtualization mechanism like a hypervisor provided in a physical computer, one or more virtual computers are constructed in the physical computer. There has been known live migration (that will be referred to as “LM”) technology in which a virtual computer in operation is migrated from a first physical computer to a second physical computer (for example, PTL 1).
In the following description, a physical computer that serves as a LM source will be referred to as a “first physical computer,” the virtualization mechanism provided in the first physical computer will be referred to as a “first virtualization mechanism,” a physical computer that serves as a LM destination will be referred to as a “second physical computer,” a virtual NIC (Network Interface Card) will be referred to as a “VNIC,” a virtualization mechanism provided in the second physical computer will be referred to as a “second virtualization mechanism,” a virtual computer (virtual machine) that serves as a LM target will be referred to as a “target VM,” the VNIC managed by the first virtualization mechanism and allocated to the target VM before the LM will be referred to as a “first VNIC,” and the VNIC managed by the second virtualization mechanism and allocated to the target VM after the LM will be referred to as a “second VNIC.”